use Benchmark qw/cmpthese/;

my %landab   = (
    "austria"      => "a",
    "belgium"      => "b",
    "switzerland"  => "ch",
    "germany"      => "d"
);

cmpthese( 0, {
    hash => sub { my %badnal = reverse %landab; my $land = $badnal{a}; },
    anon => sub { my $land = {reverse %landab}->{a}; },
});